1. Field of the Invention
The present invention relates to extraction and notice of information for notifying a mail addressee of a mail receiving error due to a capacity limit of a mail server at the time of receiving the mail.
2. Description of the Related Art
The related art of the present invention will be explained with reference to documents.
In the midst where importance on electronic mail (simply called e-mail or mail) is increasing in companies, particularly in business performance requiring immediacy, there is an increasing need of instantly receiving the mail. However, it is general that in an Internet service provider (ISP) for providing mail services, the limit is set to a capacity of a mail box for protection of a server or a contract (capacity) thereof. Therefore, there are some cases where a need of the instant reception of the mail can not be achieved, for example, the mail can not be received for the reason that the capacity of the mail box exceeds a limit value.
Examples of technologies for overcoming this situation include a method of providing another receiver (mail box) not to interrupt reception of the mail itself or a method of processing receiving mail to cut down on a capacity of the mail itself (data capacity), thus continuing to receive the mail (for example, refer to Japanese Patent Laid-Open No. H02-213252 (1990)). Further, there is a method where at the time of POP receiving, it is determined whether or not a capacity per one piece of mail exceeds a limit value, and in a case of the exceeding, only a header thereof is received, which will be notified to an addressee of the mail to avoid a reception failure of the mail (for example, refer to Japanese Patent Laid-Open No. 2001-154946). According to this method, when the remaining mail data other than the header are within a capacity allowance range of the mail box thereafter, the remaining mail data are additionally received, which will be connected to the already received header portion, thereby enabling the entire mail to be received.
Further, there is a case where, when the capacity excess occurs in a mail service, sender's address information, message ID, mail capacity and transmission date and time are extracted from a server error log (refer to FIG. 13), and the error notice mail (warning mail) is notified to a delivered mail address for each capacity excess occurrence.
Theses methods, however, have the following problems. First, in the method disclosed in Japanese Patent Laid-Open No. H02-213252 (1990), a capacity other than the contract is simply used to receive mail of a customer as it is, raising a problem that wasteful consumption of a server resource occurs. Further, this method has a problem that it is necessary to take into account twice maintainability of customer data (that is, regarding two regions of the contract capacity and capacity other than the contract).
In addition, the method disclosed in Japanese Patent Laid-Open No. 2001-154946 is a method of solving capacity lack of a reception client at the time of POP receiving by mailer software. Therefore, this method does not yet solve problems with an information notice for an addressee at the capacity lack of the reception mail box in the mail server occurring at receiving processing between mail servers, and capacity maintenance as an ISP.
Further, since, in the technology of notifying a delivered mail address of information extracted from the server log as error notice mail, the information extraction is made from the log processed in the mail server, the information to be obtained is limited to header information of the mail. Therefore, information such as a subject of the mail of the receiving error or an address of a sender can be obtained, but it is impossible at all to know the body content of the mail of the receiving error. In addition, it is also impossible to know whether or not an attachment file exists in the mail of the receiving error or what kind of an attachment file it is. In addition, in a state where the mail box of the receiver has no vacant capacity, each time new mail is sent, the error notice mail is supposed to be sent. Therefore, this method is inconvenient for a receiver.